WASHINGTON (CNN) --Iraq is becoming a major "magnet" for al Qaeda terrorists, who now pose more of a threat than remnants of Saddam Hussein's Baath Party, two analysts said Tuesday after a truck bomb killed 17 at the U.N. headquarters in Baghdad.

"A half-dozen U.S. officials who investigate or analyze al Qaeda ... say that Iraq has become an important battleground for al Qaeda in the past several months," CNN terrorism analyst Peter Bergen said.

"The officials use words such as 'magnet' and 'super magnet' to describe the attraction that Iraq has for al Qaeda and other 'jihadists,' " said Bergen, author of "Holy War, Inc.: Inside the Secret World of Osama bin Laden."

James Rubin, a former U.S. deputy secretary of state, agreed that the terrorism milieu in Iraq has changed, pointing to increased attacks against civilian targets and fewer large-scale attacks against U.S. soldiers.

"It is my suspicion that the types of attacks in Iraq are either backed or funded by Islamic extremists."

They are coming from other countries and "see it as a rich place to conduct their bloody business," he said.

"Let's face it, if you are a terrorist in the Middle East and you have a mission to kill Americans, Iraq is now the place you're going to want to go," said Rubin, speaking from London, England.

"We have had an attack on the Jordanian Embassy and attacks on water supplies and power supplies, [and] now the attacks on the U.N., which hark back very much to the attempt of the al Qaeda organization to blow up the U.N. headquarters in New York," said Rubin, who was the State Department's top spokesman during part of the Clinton administration.

Rubin was referring to a foiled plot by a group linked to al Qaeda to blow up New York landmarks, including the General Assembly building, in the mid-1990s.

Bergen said one counterterrorism official told him most of the militants are Saudis who crossed into Iraq from Syria.

Another counterterrorism official told Bergen that Iraq is as attractive to al Qaeda as Bosnia was during the mid-1990s and Chechnya has been in recent years.

Bergen said the official told him that Iraq provides "unlimited targeting, it's right in their back yard and is a very attractive cause for them."

In the past two months, about 3,000 Saudis have gone to fight coalition troops in Iraq, said Dr. Saad al-Faqih, a leading Saudi dissident based in London who has long been a reliable source of information about al Qaeda.

Al-Faqih's information comes from Saudi security sources and sources within the jihadi community in Saudi Arabia.

The Saudis who have gone to Iraq to fight have traveled there via Kuwait, Jordan and Syria, al-Faqih said.

Al-Faqih said one source describes Iraq as "almost like Peshawar during the 1980s," a reference to the city in Pakistan that attracted Muslims from around the world eager to volunteer to fight the Soviets then occupying Afghanistan.

Al-Faqih said Saudis make up about 85 percent of the foreign fighters in the country, but a few of them are Kuwaitis.

The Saudi fighters consider their actions jihad because they see coalition soldiers as unjustifiably occupying a Muslim country, al-Faqih said.

Another factor is that Saudi authorities have cracked down on al Qaeda since May, when terrorists attacked complexes housing Westerners in the Saudi capital, Riyadh, giving al Qaeda members an additional impulse to leave the kingdom.

"It seems perfectly plausible to say, well, you've got al Qaeda people moving into Iraq, and now suddenly you have car and truck bombs, which is a hallmark of al Qaeda. So it's entirely possible that this is al Qaeda," said CNN analyst Ken Pollack, a senior fellow at the Brookings Institution, a Washington think tank.

"On the other hand," Pollack said, "this may simply reflect an increase in the capabilities of ... indigenous [resistance] groups" such as Saddam loyalists, Sunni Muslims and Islamic extremists.

"We know that their operations against U.S. and other coalition forces have been getting increasingly more sophisticated," said Pollack, author of the 2002 book "The Threatening Storm: The Case for Invading Iraq."

"We know in general terms who's behind it," Bremer said. "It's people who are fighting against the liberated Iraq that most Iraqis have welcomed. It's people who do not share the vision of a free Iraq with a vibrant economy.

"These are probably people left over from the old regime who are simply fighting a rear guard action by attacking Iraq's assets," he said.